In development processing of a photographic material, in general, the case where an automatic developing machine (hereinafter referred to as "automatic processor") is used has increased for its rapidity, easiness and handleability. In recent years, requirements for the reduction of replenishing rate in development processing and the speed-up of development processing have increased more and more. One means to satisfy these requirements is to increase the activity of a developing solution. In processing a black-and-white photographic material, the activity can be enhanced by increasing the concentration of a developing agent, but it causes extreme deterioration of the developing solution due to air oxidation. Further, reduction of the film thickness of a photographic material (e.g., a protective layer) is also effective for rapid processing.
The use of sulfite for preventing the deterioration of a developing solution has been known for long but sulfite has a function of dissolving a silver halide, therefore, silver is dissolved out as a sulfite silver complex from a photographic material into a developing solution. This silver complex is reduced in the developing solution and adheres to a developing tank and a roller and gradually accumulates. This is called silver stain or silver sludge, which necessitates periodical cleaning and maintenance of the instrument because it adheres to the photographic material to be processed and contaminates images or the automatic processor.
As a method of diminishing such silver stain, methods of adding compounds which depress silver ions dissolving into a developing solution and/or restraining the reduction of silver ion to silver as disclosed in JP-A-56-24347 and JP-A-8-6215 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") are known. However, to obtain sufficient silver stain-preventing effect by such methods, the addition amount of the former compound should be increased, which causes harmful influences on photographic characteristics such as desensitization and increase of fog. Such disadvantageous influences are remarkable, in particular, in an ultrahigh contrast photographic material containing a hydrazine compound. Further, with respect to the latter compound, although contamination of the lack and the tank of an automatic processor is effectively prevented because of its high reduction-restraining capability, but when a photographic material is practically processed, the reduction at the contact place of a roller and a photographic material where the silver concentration is locally high cannot be prevented sufficiently. Therefore, silver precipitates on a roller. This adheres to a photographic material and causes silver stain.
On the other hand, the addition of an ascorbic acid to a developing solution is already known. An ascorbic acid is used as a developing agent in many cases as disclosed in British Patents 956,368 and 1,030,495, U.S. Pat. No. 2,688,549 and JP-B-36-17599 (the term "JP-B" as used herein means an "examined Japanese patent publication"). In these patents or publications, an ascorbic acid is used as a developing agent and a hydroquinone derivative is not contained in the developing solution. The effects of these inventions are different from the effect of an ascorbic acid according to the present invention. If an ascorbic acid is added to an alkaline developing solution in an amount of 0.15 mol or more, there arises a problem such that the ascorbic acid is air oxidized and the pH lowers at hydrolysis, and the activity of the developing solution decreases.
A combined use of a hydroquinone derivative and an ascorbic acid are disclosed, e.g., in U.S. Pat. No. 3,512,981, JP-B-55-49298 and British Patent 1,326,495, but these patents are directed to a lith type development system of a photomechanical process, in which free sulfite ion concentration is low. Therefore, there is a problem that the preservability of a developing solution is not stable.
A combined use of a hydroquinone derivative, an ascorbic acid and a 1-phenyl-3-pyrazolidone derivative in a developing solution is disclosed in U.S. Pat. No. 3,865,591, but the ascorbic acid in this patent functions as a developing agent, and there are no descriptions about the effects of the ascorbic acid in the present invention. Further, because the pH of the developer in the above patent is as low as from 8 to 9.5, the activity is low. Thus, the above developing solution is differently aimed at from the present invention.